Previous apparatus for retaining springback reflectors or panels in a stowed position required the use of separate retaining hardware for the reflectors and the support panel structure. In order for these prior apparatus to operate, some of the retaining hardware was secured to the springback reflectors rendering the prior designs inefficient and expensive.
These designs were inefficient because the retaining hardware added additional weight to the reflectors that could affect both its deployed frequency as well as the reflector's shape after its unfurling and deployment. Additionally, the initial relative motions between the reflectors and the retaining hardware created a risk that some of the retaining hardware would bind to the reflectors during the retraction phase, which would prevent the reflectors from unfurling properly.
More specifically, the retaining hardware of these prior designs included a bolt or a pin that restrained the springback reflectors and kept them in a stowed position and held the support panel mechanism in stowed position. In order to retain the reflectors, the bolt was passed through both the reflector surfaces. In order for the reflectors to separate, the bolt had to be retracted from engagement with the reflectors. After retraction, the bolt was retained in a catcher tube. The catcher tube was mounted on the outer surface of one of the reflectors which added additional weight and caused potential operational problems.
To remove the bolt or pin that passed through the reflectors and held the support panel mechanism in a stowed position, the bolt or pin needed to be retracted normal to the initial motion of the reflectors as they unfurled, creating risk during the deployment sequence. However, there currently are no commercially available pin pullers with a retraction length sufficient to allow the pin to be fully retracted from engagement with the reflector shells and the support panel deployment mechanism. Nested shear cones were also mounted to each reflector surface to accomplish shear transfer which also added additional weight. Thus, these prior designs are both impractical and costly.
As an alternative solution, multiple pyrotechnic devices could be utilized to actuate the support panel deployment. This would alleviate the need for a long pin puller. However, the inclusion of multiple pyrotechnic devices would add further cost and weight to the system.